I’m in between spray coats of polyurethane right now on a project I’m building for a client. At posting it’s 36 degrees F outside and dropping. To speed dry time, I’ve got the shop sealed up with 2 electric heaters going, (normally an unheated space).
While the heaters are doing a decent job at keeping the temperature above 55 or 60, I’m wondering if it’s a better idea to open the doors so there can be a better air exchange. The finish is supposed to take 3-4 hours, but I’m averaging 7-10 hours in some spots.
I’m sure it’s better to keep things warmer than colder, but at what point do you sacrifice one for the other?
*(Just as a note, I turn the heaters off while spraying and open the garage doors slightly to get a small cross breeze, to mitigate any chance of explosion!)
Thoughts?
Replies
First off, you'd have to spray A LOT of poly to generate an atmosphere capable of an explosion. Lacquer, on the other hand...
There are better, more experienced voices here, but I think you're better off keeping the space warm -- preferably, warmer than the 50-60 degrees you have it now. A warmer room will speed up the drying time of the poly.
♫ If you’re OCD and you know it wash your hands ♫
Yeah, ok. I've got both heaters maxed out, and cant really bring the temp up significantly. Maybe I'll go buy a better heater!
Make a temporary tent out of plastic sheeting that you can hang around the work or to make the work area smaller so your heaters are more effective. Not knowing your shop the idea is to make a smaller area that you have to heat.
Tom
PROBLEM SOLVED! I found a torpedo construction style propane heater on Craigs List for not too much, and it's cranking out 85,000 BTU's. Got it up to 80 in there already! Woop!
Unless your shop is exceptionally airtight, the normal leakage of air will provide enough ventilation to keep up with the evaporation of the solvent.
The 3 to 4 hour drying time is based on a 72 degree (F) air temperature, the lower temperature in your shop would account for the much slower drying.
I would try to get the temperature a bit higher since at some point certain finishes never seem to harden properly if they are cured at too low of a temperature. I would try to find out from the manufacturer, if the information isn't on the can, what the lowest recommended drying temperature is.
Shop Manager for FWW Magazine, 1998 to 2007
I don't know if this affects your finish, but those heaters create a lot of moisture in the air. But they do put out the heat.
John
Hadn't thought of the moisture bit- but the air here is dry desert air, even when cold any snowy for the most part. Hopefully it shouldn't effect it too much-
Sounds like there's not an easy cheap fix! If I turn on the electric heaters I'm burning up the power bill, propane eats up the oxygen, creates carbon monoxide and moisture, adding a wood stove or anything permanent is out too.
When I build my permanent shop, a radiant floor system is going in for sure!
Where are you? I'm near four corners, sounds like a similar climate.John
Recreation Mecca Bend, Oregon. 32" of snow average, 300 days of sunshine, half hour from 9000 foot Mt Batchelor.
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